Plate Tectonic and Continental Drift

Warm up A tree grows from a tiny seed into a huge, 200-foot tall

redwood. Most of the redwoods trees structural mass came from _______.

A. Minerals in the soil. B. Carbon dioxide in the air. C. Oxygen in the air. D. nitrogen in the soil.

Warm up- Happy New YearIdentify two organisms below that share the same trophic level.

A. elephants and lions .B. Chipmunks and squirrels.C. Cheetahs and giraffes.D. Wolves and rabbits

History of Continental Drift Alfred Wagener, 1910 Theory of Continental Drift

CONTINENTAL DRIFT. The continents are drifting on top of the ocean floors. They once were together in a massive continent called Pangaea.

Proof one Map fit of the continents Proof two Fossils of plants and animals where they can not exist. Exactly same rock on two different continents. Evidence of glaciers in deserts and deserts in Alaska

Against this theory No evidence of scarring of seafloor, no debris Could not explain mechanism of movement.

Pangaea

Harry Hesse

Hess a geologist studied the MAR during WWII looking for submarine. Later he helped prove that the sea floor was spreading in the Atlantic ocean. He was also the first head of NASA.

Harry Hess Plates move on the asthenosphere Asthenosphere is an elastic layer between the hard crust and

the molten mantle. In the Mid Atlantic Ridge (MAR) the earths crust is spreading. DIVERGENT BOUNDARY In the Himalayas and Andes the plates are colliding and

building mountains. CONVERGENT BOUNDARY Where an ocean plate is forced under a Continental plate,

Subduction occurs, causing Volacanoes. Italy and Washington State.

Subduction Convergent Boundary

Boundary Types

Draw and label these

Divergent Boundaries-Pulling away from each other.

Mid Atlantic Ridge = (MAR)is a divergent boundary.

Convergent Collision Boundary

Himilaya Mtns – where indo-australian plates hits asia plate.

Subduction zones

San Juan de Fuca Plate – the subduction zone that creates U.S. Volcanoes, in washington state.

Transform boundaries – side by side collisions-create faults and earth quakes.